Dimitar Berbatov believes Marcus Rashford and Anthony Martial can be "unbelievable" players for Man United

The pair played second-fiddle to the likes of Romelu Lukaku and Alexis Sanchez for much of last season, with Martial missing out on a place in France’s successful World Cup campaign as a result.

Rashford went to Russia with England and has played plenty of football under Jose Mourinho, although the 20-year-old failed to impress his boss when given the chance to make a mark late on in the campaign.

With minutes key to his continued improvement, Rashford needs to remain central to Mourinho’s plans, while Martial continues to be linked with a move away from Old Trafford.

The winger left United’s pre-season tour of the United States earlier this week with Mourinho confirming he left to be present at the birth of his child.

Berbatov, who starred up front for the Red Devils between 2008 and 2012, wants to see more from the United youngsters moving forward.

“I think Rashford needs more playing time so he can develop fully because he has great abilities, for me alongside Martial these two can be unbelievable,” he said.

“They are young, they enjoy the game and because of their youth they see the game differently to other players.”

Berbatov played for United from 2008-12.

United’s pre-season tour has been something of a damp squib thus far, with three draws from their three games – culminating in a penalty shoot-out win over AC Milan on Wednesday.

There are a number of players missing, those who played in the World Cup and injured skipper Antonio Valencia, but Berbatov is hoping to see Rashford and Martial play alongside one another at some point.

“Some people say they cannot play at the same time but I disagree,” added the 37-year-old Bulgarian, who bagged 56 goals in 149 appearances for the club.

“They don’t over-think things, they just go and play and enjoy the game as much as they can – they are quick, strong, have great technical ability and they can score goals.

“So I hope that more time is given to Martial and Rashford which I think will be beneficial to the whole team and to them as well obviously.”

Young is one of a host of United stars still absent after World Cup duty, but could seize his chance with Antonio Valencia and Diogo Dalot both ruled out for the start of the new Premier League campaign.

Mourinho told a press conference: “Ashley Young is a possibility to play at right-back. He is on holiday and I don’t know if he fancies being back before that to put himself available for the team – or if he prefers to stay on holiday.”

Mourinho confirmed he will allow Darmian to leave the club providing they receive a suitable offer, but reserved praise for the 28-year-old.

Mourinho added: “Darmian is a fantastic guy and a tremendous pro. He’s the kind of guy who is always ready to give what he has, and for him to play against his childhood club and be captain has a nice meaning.

“But he wants to leave and I think when a player wants to leave if the right offer arrives you have to be human and let the player follow his instincts, but not at any price.

“Until now the offers we have got for Matteo are not even close to being accepted.”

Out of favour at United: Darmian.

Contrary to newspaper reports implying his anger, Mourinho appeared to have adopted a more laid-back approach to Anthony Martial’s decision to leave the tour early.

Mourinho said he was told three days ago by Martial – who is expected to leave Old Trafford this summer – that he was flying back to Paris to attend the birth of his second child.

Mourinho added: “I found out Martial was going to Paris when he told me three days ago.

“When a man is going to be a father, in this case for the second time, and he decides that it’s very important for him to go, I think nobody has the right to stop him to go.”

New father: Anthony Martial.

The manager shrugged off the win on penalties, insisting it meant “nothing”, but goalkeeper Joel Pereira was delighted to play his part with several saves – and attributed his success to a series of training-ground bets.

He told MUTV: “It feels amazing, as a goalkeeper when it’s a penalty shoot-out it depends on you.

“I’ve been the third goalkeeper for a year now and I always stay after training doing finishing with the boys – I like to do some bets with them, do some penalty shoot-outs and bet a shirt or dinner or something.

Among the problem areas identified has been the heart of defence. Mourinho has bought one centre-back in each summer he’s been at the club – Eric Bailly in 2016 and Victor Lindelof last year. However, there are still questions regarding both players, as well as the senior figures he inherited – Marcos Rojo, Chris Smalling, and Phil Jones.

United have thus been linked with a host of different options to reinforce the back-line, and here we run the rule over the five most prominent names in the rumour mill.

Harry Maguire

The Leicester City man is both the traditional English defender – no-nonsense, strong in the air and in the tackle – and the prototypical modern centre-back, good with the ball at his feet, a solid distributor, and a potent attacking threat, which he showed at the World Cup.

His per-game stats from the Premier League show why he’s being linked with a move to United. Last season, he won 62 per cent of his duels, best of anyone on this list. He won more tackles per 90 minutes in the league than anyone bar Yerry Mina – who only played two league games for Barcelona.

Maguire also beats out everyone (again, bar Mina in his two-game cameo) for successful take-ons (85 per cent) and his key passes per 90 statistic (0.36) is commendable as well.

Fit for United: 9/10

Is Harry Maguire United-bound?

Toby Alderweireld

Alderweireld is the other defender who’s been heavily linked with United, and it’s likely that only Tottenham chairman Daniel Levy’s hardball negotiation tactics kept a move for the Belgian from being sealed before the World Cup. Like Maguire, Alderweireld is tough-nosed defender who is also comfortable joining the attack, and provides a goal threat both in the air and with a fierce shot.

He’s good on the ball – he won 83 per cent of his take-ons and had a pass accuracy of 86 per ecnt last season, and he has a penchant for playing long, raking balls over the top which players like Romelu Lukaku will love. However, he wins fewer aerial duels than anyone else on this list – a shockingly low 34 per cente last season – which, under Mourinho, will be a problem.

Fit for United: 5/10

Is Alderweireld too big a risk for Mourinho?

Leonardo Bonucci

While Bonucci was at Juventus and playing alongside Giorgio Chiellini, he seemed like the classical Italian defender. But his time at Milan revealed a flaw. He styles himself after Franz Beckenbauer, with a love for bringing the ball out and joining attacks – something he’s quite capable of. But his attacking forays left the Milan defence exposed too often for a defensive manager’s liking.

Defensively, then, Bonucci can be a weakness unless there’s cover for him. He only won 53 per cent of his aerial duels in the league last season, lower than anyone else on this list apart from Alderweireld, and his tackles won per 90 number, 0.66, is far lower than the rest.

Does his attacking ability – an 85 per cent passing accuracy, 0.5 key passes per 90 minutes, and a goals scored mark (0.07) that’s the best of this class – make up for that? In Mourinho’s book, probably not.

Fit for United: 4/10

Bonucci has a reputation as one of the world’s best defenders – but the numbers say otherwise.

Jerome Boateng

Boateng is much like Bonucci and Alderweireld in that his reputation is based on his distribution and attacking ability as much as defending – if not more so. He’s a stylish centre-back who’s good on the ball, but can get caught out defensively.

The numbers bear that out – he had more defensive errors and errors leading to goal per 90 minutes last season than any of these five (0.07 for both), and his tackling number is lower than Maguire’s (0.99 to 1.23). He does have more key passes than anyone – 0.55 per 90 – and an 87% pass accuracy, but the defensive numbers will give Mourinho pause.

Fit for United: 5/10

Boateng has lost his sheen over the last couple of years through injury and a dip in form.

Yerry Mina

Being a Barcelona target says much about Yerry Mina – they thought he’d fit the mould as a passing centre-back who could challenge Gerard Pique and Samuel Umtiti. Along with that, he also fits the traditional stylings of a defender, especially for England – almost nothing gets past him in the air, and he’s a solid tackler.

Statistically, Mina’s small sample size goes against him – he only played two league games for Barcelona and even his World Cup numbers are based on four appearances. The most remarkable aspect of those four appearances was that he scored three goals, while his tackles per game (1.3), interceptions (1) and passing accuracy (90 per cent) compare favourably to everyone else.

The question is whether Mourinho thinks it’s worth taking a calculated gamble On Mina, when his defence is seemingly crying out for experience and a leader.